Separation of pesticides by high-performance liquid chromatography with amperometric detection

The possibility of the amperometric detection of a number of pesticides, such as benomyl, thiram, linuron, metoxuron, desmedipham, dicuron, lenacil, and fludioxonil, widely used in agrochemical practice was studied. The effect of the working electrode material (glassy carbon, nickel, and gold) and the type of the electrochemical cell on the value of the analytical signal was studied using the example of thiram. It was found that the optimum potential of the working electrode in analyzing a pesticide mixture was 1400 mV. The dependence of the analytical signal on the pesticide concentration was shown to be linear. The detection limits for the analytes were calculated. Using a 100-mu L sample loop, all of the studied pesticides can be determined at the level of the maximum permissible concentration (MPC). The amperometric determination of seven pesticides at the level of MPC in real samples was shown by the examples of model mixtures dissolved in tap water and beetroot juice.